Fracture analysis of epoxy-aluminum spacers exposed to pressure loads

The paper presents a fracture mechanics approach to estimation of a critical load of a bi-material structure. The structure is a simple composite disc where the inner cylinder is made of aluminum and the outer cylinder is made of filled epoxy resin. The part is constrained on the outer perimeter and subjected to a pressure load from one flat side. The conventional finite element method was employed in order to determine fracture mechanics parameters – generalized stress intensity factors (H1, H2). Initially the junction was considered as a bi-material notch (free edge), where one real exponent of stress singularity can be found. In the second approach, the interface pre-crack was considered. This case is characterized by the complex exponent of the stress singularity. For the prediction of unstable crack propagation, the mean tangential stress failure criterion was used.